These mostly seem a
little bit powerful so I'll try and add a little IVAN flavor here for balance/humor:
Helm of telecontrol:
-Not sure we actually need this with the rings around. I do like the idea of having more interesting and varied helmets, but I don't think we need to have a tele-helmet unless it does something better than the rings like preventing equipment from vanishing from your body.
Helm of telepathy:
-Grants ESP... but the helmet has no eye holes, so you can't see. PER 1. This preserves the (imo good) difficult decision of whether to use ESP or AoLS because the amulet of ESP doesn't mess with your stats. Not being able to see isn't
too heavy a penalty because you'll be able to sense (most) enemies and you can always take the helmet off if you need to.
Amulet of magic breath:
-I like this idea actually, no further comments. I have also considered whether adding a consumable item that grants temporary gas immunity would be a good idea. Currently the only way to temporarily get gas immunity is through volatile magic effects like magic fart clouds and eating mushrooms.
Amulet of Speed:
-The amulet is made out of bone or ommel tooth and is also hasted at all times.
Dragon Cuirass:
-Would probably be a good treasure for the dragon tower (or found elsewhere to prepare for it?) Otherwise doesn't need any changes.
Belt of Giant Strength:
-I'm not sure having this is such a good idea in general - also it reminds me of LIVAN's thieves' girdle which was really useful. Perhaps a good penalty for this would be that it also weighs a tonne - now it really is the counterweight to the belt of levitation